Boilers



May 24, 1960 c J. MccoRQuoDALl; SIMPSON BOILERS 2 Sheets-Sheet 1 Filed Nov. 15, 1957 Inventor CHARLES J. SIMPSON Patent Agent May 24, 1960 c. J. MCCORQUODALE'SIMPSON ,6

' BOILERS 2 Sheets-Sheet 2 Inventor CHARLES J. SIMPSON Patent Agent GASES WATER Filed Nov. 15, 1957 United States Patent BOEERS Charles John McCorquodale Simpson, 583 Jarvis St.,

Apt. 28, Toronto, Ontario, Canada Filed Nov. 15, 1957, Ser. No. 696,825

Claims. (Cl. 122-140) This invention relates to new and useful improvements in water tube boilers of the shell type whereby the same may be adapted for domestic heating and the like.

Prior water tube boilers utilized in domestic installations are characterized by the requirement of a substantial amount of refractory both in internal and external linings. Aside from high cost of installation involving the use of large amounts of refractory and hence heavy labour cost, maintenance costs are high due to the necessity of preserving the refractory. This disadvantage alone has been suflicient to allow water tube boilers to fall gradually into disuse for domestic installations. Another main disadvantage of prior water tube boilers is the high cost of water tube replacement. In general prior designs of water tube boilers present great difiiculty of access to the water tubes for repair or replacement. The complication of such prior structures has been sufficient to render them impractical for servicing except on larger scale industrial installations where their eificiency of operation is essential and the larger geometry of the structure permits easier access for servicing and maintenance. I

It is the main object of this invention to provide a water tube boiler of the shell type having the high heat conversion efficiency characterized by this class of boiler but substantially modified in design and construction to provide for a minimum of refractory utilization.

.It is a further object of this invention to provide an improved water'tube boiler of the shell type as set forth herein in which the components are of simple geometery for'ready access for servicing and are separable as units for facility of manufacture, shipping, assembly and replacement.

It is a still further object of the invention to provide an improved water tube'boiler of the shell type having an outer shell wrapper or casing having front and rear head end walls supporting therebetween an internal unit com prising a secondary combustion chamber immersed in water'in spaced relation within the shell wrapper and containing a bank of straight convection tubes through which the water is adapted to circulate by convection and past which'combustion gases flow from the secondary cornbustion chamber receiving gases from the primary combustion chamber exterior of the front head wall and defined by a plurality of enclosing U shaped tubes forming aprirnary convection bank extending forwardly from the front head wall and communicating water by convection from the lower to the upper portion of the boiler, the said .primary combustion chamber being adapted for the accommodation of any conventional combustion unit such as an'oil burner or solid fuel burner of the domestic type.

Other objects of the invention will be appreciated by a study of the following specification taken in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a perspective view of the improved water tube shell type boiler of the invention having portions thereof removed to reveal the primary combustion chamber construction and inclined refractory baflle leading therefrom to the secondary combustion chamber con- 2,937,626 Patented .May .24, .1960

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tained within the internal unit shown-supported in spaced relation within the shell casing.

Figure 2 is a diagrammatic transverse sectional elevation on the line 2-2 of Figure 1;

Figure 3 is a diagrammatic plan sectional view on the line 3-3 of Figure. 2 but revealing in addition the location and general nature of the primary combustion chamber;

Figure 4 is a perspective view of the internal unit of the boiler of the invention and showing the unit partially cut away to reveal details of construction.

Figure 5 is a perspective view of the unit of Figure 4 showing the same installed within the shell casing in spaced relation within the latter and supported therein by the head end walls, the path of the gas flame or combustion products being indicated by chain line arrows and the path of convection Water being indicated by arrows comprising a repeating dot and 'dash line revealed also in the legend for this figure;- v

Figure 6 is an external perspective view of the water tube boiler of the invention showing the location of an oil burner combustion unit thereon wherein the general arrangement of the components corresponds to the view of Figure 1. V

In the drawings the improved shell type water tube boiler of the invention is revealed in its general componentsin Figure 3 and' comprises a burner or combus tion source 10 delivering hot gases on the path-Y into the primary combustion chamber 11 which gases pass into a secondary combustion-chamber 12 comprising an internal unit -13 supported between the head end walls 14 and 15 -of a shell teasing or housing 16 surrounding the internal unit in spaced relation thereto to provide a water reservoir or chamber 17 communicating liquid by convection and by the tubes 23 of the internal unit belationship except Where they connect to'the top and bottom of the front head plate -14. These tubes are covered with a layer of soft installation 19 having an exterior light metal casing 20a. As shown in Figure 3 an exterior metal casing or housing'21 may be provided in spaced relation to the primary combustionchamber casing 20a. The location of the burner 10 is such that the combustion gases are caused to change direction in the primary combustion chamber prior to exit therefrom for communication to the secondary combustion chamber 12 provided by the internal unit 13.

The internal unit 13 comprises a convection bank 22 formed of a plurality of straight tubes 23 for convection Water connecting between the tube supporting plates 24 and 25, A secondary combustion chamber wrapper sheet 26 is welded as at 27 and 28 to the tube plates 24 and 25 to form a rigid structure therewith 'defining a secondary combustion chamber in the contained space 29. An inclined baflle formed of suitable refractory material 30, also revealed in Figure 1, directs the combustion flame toward the upper curved chamber portion 31 for downward deflection by the latter into the space 29'from which the gases pass between the tubes 23 to the flue gas exit chamber 32 formed by the exit chamber side wall 33 welded as at 34 and 35 to the tubeend 27 of the exit chamber 32. Y

The structure disclosed is par- The front and rear head walls 14 and 15 respectively support the internal unit 13 in spaced relation to the shell casing 16. The internal unit is provided in a unitary form capable of entire-replacement by removal from the shell head end walls. Each of the'head walls is cut away such as indicated by the'chain lines 38 and 38a in Figure 2 to accommodatethe internal unit and provide support therefor. The rear wall of the internal unit comprises a built-up ceramic panel 39 whereas the front wall of the unit is provided by a built-up ceramic flame barrier 36 extending over the front surfaces of the convection tube bank 22 and the front of the gas exit chamber 32 as shown in Figure 3. The internal unit is held in spaced relation to the shell 16 thereby providing a water reservoir or chamber 17 therebetween adapted for the heating of convection water as indicated by the arrows in Figure 2.

In operation the combustion gases, as shown in Figure 5, pass transversely across the primary combustion chamber and are deflected at right angles thereby to enter the secondary combustion chamber by way of the deflecting upwardly inclined baffle 30 and downwardly deflecting combustion chamber portion 31 giving rise to a higher degree of turbulence in the secondary combustion space 29 from which the gases pass between the tubes of the convection tube bank 23 to the exit flue chamber 32. The convection tube bank 22 is inclined vertically or tilted toward the secondary combustion chamber whereby the flue gas exit chamber is disposed at slightly greater elevation as compared with the elevation of the combustion chamber. Furthermore the flue gas exit chamber 32 in its upper portion 40 diverges slightly upwardly toward the exhaust opening 20 in the re fractory wall 39 (see Figures 2 to whereby the natural arrangement of components is conducive to gas flow throughout the structure. In addition, however, the thus afforded inclination of the convectlon tubes 223 permits a highly convenient location of service openings 41, see

Figures 2 and 6, whereby the tubes are readily accessible for replacement or servicing by established methods. The inspection opening 42 enables servicing of the lower regions of the shell casing and the removal of sludge. The service openings are closed by conventional covers of any suitable known design and therefore require no explanation as to constructional detail. p 7

The water tube boiler of the invention may be supported on a floor frame 43 of welded construction as indicated in Figures 1 to 6 and fastened to the shell'16 by suitable legs 44. The complete water tube boiler may therefore be provided in a form transportable as a complete unit for installation. In the event servicing is required, all components requiring servicing are readily accessible. In the case of the primary combustion chamber, convection tubes 18 maybe of two selected diameters as is indicated in the drawing of Figure l. The removal of the metal casing 20a enables quick access to any tube through the insulation 19 for replacement thereof. Water inlet and outlet openings 45 and 46 may be provided at any suitable location as indicated in Figure 2. The water level should be maintained at a depth immersing the internal unit as is indicated by the level 47 of the water 48 in Figures 2 and 5.

What I claim as my invention is:

1. In a water tube boiler of the shell type having a water containing outer shell casing in the form of a tubular wrapper closed at its ends by front and rear head end walls the combination therewith of: a primary combustion chamber exterior of said front wall; a plurality of water tubes enclosing said primary combustion chamber and communicating water from within the lower regions of said casing to the upper regions thereof and means extending from said fronthead end wall exterior thereof about said water tubes thereby to define a chamber therewithimflame generating means disposed to direct a flame transversely of saidcombustion chamber; an internal unit' having a longitudinally extending secondary combustion chamber and a longitudinally extending exhaust gas chamber; a gas communicating heat exchange structure in the form of a bank of substantially vertical parallel straight water conducting tubes separating said exhaust gas chamber and said secondary combustion chamber, and an enclosure for said chambers and bank having communicating apertures for said tubes for passage of water therethrough; an opening in each of said end walls having marginal edges supporting the enclosure of said internal unit providing the sole support therefor in spaced relation within said tubular wrapper and disposing said secondary combustion chamber in communi cation with said primary combustion chamber remote from said flame generator at said front head end wall; means covering the opening in said rear head end wall and having an exhaust flue opening for said exhaust chamher, and means covering the opening in said front head end wall substantially only over said convection tube bank and said exhaust chamber.

2. A water tube boiler as claimed in claim 1 and a flame deflecting baffle disposed within said internal unit adjacent said primary combustion chamber and having deflecting surfaces inclining upwardly and rearwardly.

3. The water tube boiler-as claimed in claim 1 and a service opening in said casing located above said internal unit; and a service opening in said rear head end wall located for access to the interior of said casing below said internal unit.

4. A water tube boiler as claimed in claim 1 in which said covering means comprises a ceramic material sup ported entirely by the enclosure of said internal unit.

5. A water tube boiler as claimed in claim 1 in which said bank of convection water tubes of said internal unit is inclined upwardly toward the secondary combustion chamber thereof.

6. A water tube boiler as claimed in claim 1 in which the exhaust chamber is disposed within said casing at a slightly higher elevation than said secondary combustion chamber and said bank of convection water tubes is disposed at a vertical inclination toward the secondary combustion chamber.

7. A water tube boiler as claimed in claim 1 and a flame deflecting baffle disposed within said internal unit adjacent said primary combustion chamber and having deflecting surfaces inclining upwardly, and rearwardly; a service opening in said casing located above said inter- -nal unit; and a service opening in said rear head end wall located for access to the interior of said casing below said internal unit. V

8. A water tube boiler as claimed in claim 1 and a flame deflecting bafile disposed within said internal unit adjacent said primary combustion chamber and having deflecting surfaces inclining upwardly and rearwardly; said covering means comprising a ceramic material supported entirely by the enclosure of said internal unit.

9. A water tube boiler as claimed in claim 1 in which said covering means comprises a ceramic material supported entirely by the enclosure of said internal unit; and in which said bank of convection water tubes of said internal unit is inclined upwardly toward the secondary combustion chamber thereof.

10. A water tube boiler as claimed in claim 1 in which said covering means comprises a ceramic material supported entirely by the enclosure of said internal unit; and in which the exhaust chamber is disposed within said casing at a slightly higher elevation than said secondary combustion chamber and said bank of convection water tubes is disposed at a vertical inclination toward the secondary combustion chamber.

References Cited in the file of this patent UNITED STATES PATENTS Barber June 28, 1904 

